Molding method for vehicular lamp part and molding apparatus for vehicular lamp part

A molding apparatus for molding a vehicular lamp part having an undercut portion that has a surface that slants with respect to a die closing/opening direction of a movable die, comprising:

• a fixed die which closes together with the movable die to define a cavity;
• an extrusion plate positioned on a first side of the fixed die, with the movable die disposed therebetween, and which is movable in the die closing/opening direction;
• a separate push-up block, forming a portion of the cavity defined by the movable die corresponding to the undercut portion;
• a push-up pin comprising a first end integrally to the push-up block, a second end turnably held by the extrusion plate, and a middle part inserted into an insertion hole formed in the movable die;
• and
• the movable die comprising a gap formed between the insertion hole and the push-up pin that enables the push-up pin to tilt,
• wherein, the movable die is movable in the die closing/opening direction, and the extrusion plate is movable in the die closing/opening direction relative to the movable die to release the vehicular lamp part from the movable die, and
• wherein, the push-up pin is tilted, after the release of the vehicular lamp part from the movable die and its corresponding movement further in the release direction, when the slanted surface of the undercut portion pushes the die surface of the push-up block in a direction that intersects with the die closing/opening direction, thereby freeing the push-up block from the undercut portion.

A molding method, comprising:

• molding a component in a molding cavity defined by a fixed die, a movable die, and a push-up block, the component comprising an undercut portion at least partially defined by the push-up block to have a surface that slants with respect to a die opening/closing direction;
• opening the molding cavity by moving the movable die in the die opening/closing direction;
• moving an extrusion plate relative to the movable die so that a push-up pin, movably mounted on the extrusion plate and fixed to the push-up block, separates the push-up block from the movable die, thereby separating the component from the movable die;
• and
• tilting the push-up pin to separate the push-up block from the component.

A molding apparatus, comprising:

• a fixed die, a movable die, and a push-up block defining a molding cavity to form a component, the component comprising an undercut portion at least partially defined by the push-up block to have a surface that slants with respect to a die opening/closing direction;
• an extrusion plate, movable with respect to the movable die in the die opening/closing direction;
• and
• a push-up pin movably mounted on the extrusion plate and fixed to the push-up block, the movable die having an insertion hole through which the push-up pin extends, the insertion hole having a diameter larger than the push-up pin to allow the push-up to tilt so that the component can be separated from the push-up block.